Persistent primary insomnia (PPI) is a prevalent and debilitating sleep disorder which in middle-and older-aged adults typically presents as an unrelenting difficulty maintaining sleep. This project will evaluate the effectiveness of a cognitive-behavioral therapy (CBT) specifically designed for the treatment of sleep-maintenance insomnia. The Specific Aims of this project include: (1) testing the effectiveness of CBT for treating the sleep-maintenance problems of middle- and older-aged PPI patients through comparisons of this treatment with an alternate behavioral therapy, relaxation therapy (RT) and a placebo control (PC) treatment; (2) comparing the treatment response of sleep-maintenance insomniacs who receive CBT on an immediate basis with those who receive this treatment after first receiving a placebo treatment; (3) comparing the effects of CBT, RT and PC on sleep architecture; and (4) comparing the effects of these three treatments on measures of anxiety, depressed mood, insomnia-related symptoms, and daytime functioning. Seventy-eight subjects between the ages of 40 and 80 will undergo polysomnographic evaluation, home sleep monitoring with a sleep assessment device, and sleep log monitoring. Subjects will also complete the Beck Depression Inventory (BDI) before treatment. By random assignment one third of the subjects will then receive CBT, a second third will be provided RT, and the remaining third will receive the PC. Each subject will be provided treatment in 6 weekly individual therapy sessions by one of two participating therapists. Immediately following treatment all pre- treatment measures will be repeated. Subjects assigned to CBT or RT will then complete a follow-assessment 6 months later. PC subjects will be provided 6 weeks of CBT and reassessed both at the conclusion of this therapy and again 6 months later. A series of multivariate statistics and tests of clinical significance will be conducted to address the Specific Aims noted above. Results will be useful for increasing understanding of primary sleep-maintenance insomnia and for improving treatment of this condition.